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W. R. KING & F. WYATT. PROCESS OF FORMING CALCIUM OARBID. No. 562,402. YPatented June 23, 1896.

INVENTOBS V akag7; I

ANBREW B GRAHAM.FHDTBUTNOWASHINGTDNDC NITED STATES ATENT FFICE,

WILLIAM R. KING AND .FRANCIS XVYATT, OF NEW YORK, N. Y.

PROCESS OF FORMING CALCIUM CARBID.

SPECIFICATION forming part of Letters Patent No. 562,402, dated June 23,1896.

Application filed April 14, 1896. $erial lie, 587,554. (No specimens.)

To all whom it may concern.-

Be it known that we, ILLIAM R. KING, a citizen of the United States, andFRANCIS IVYATT, a subject of Her Britannic Majesty, residents of thecity, county, and State of New York, have made certain new and usefulImprovements in Processes of Forming A Calcium Garbid, of which thefollowing is a been found necessary to wait, after a quantity of calciumcarbid has been formed by the action of an electric-arc furnace, aconsiderable time for the furnace and its charge to cool before removingthe charge and recharging. Many ingenious attempts have been made toincrease the capacity of such furnaces and to diminish the time duringwhich the furnace has to remain idle; but the delay is still veryconsiderable and seriously interfcres with the commercial manufacture ofcalcium carbid. There are very many other serious difficulties in theprocesses heretofore employed, which will readily suggest themselves topersons who are practically familiar with this art, and as far as we areaware, no thoroughly satisfactory process of forming calcium carbid hasas yet been found.

Our improved process enables us to dis: pense altogether with a furnaceand does away entirely with the necessity of waiting for the substanceunder treatment to be cooled before a second charge can be operatedupon. In this way our process becomes substantially continuous, thecurrent being turned off for such a short time that the aggregate ofsuch stoppages in a days run is of practically little importance.

To carry out this invention and secure the desired results, we firstmake a heap of pulverized coke and ground lime of any desired height.This may be a simple heap or mound of ordinary hillock shape in the openair, or the sides may be shored up to prevent the mound from taking uptoo much room, if preferred. This shoring up may be done by woodenplanks, bricks, or any other material desired, but is not in any sensenecessary to the carrying out of the process. V e then force downwardthrough the center of this heap until it reaches a point sufticientlynear the bottom to allow the insertion of an electrode, a core of goodconducting material. Of course,if desired,the electrode may be first putin position and the mound made over it. Electric connection is made withthe lower end of this core through the electrode. The upper end of thiscore is thenelectrically connected by means of an elect-rode to theother pole of a battery or dynamo-machine and the mixture of coke andlime heaped up around this point of connection to a sufficient height toshut out the air. Either a direct or an alternating current may beemployed, as preferred. The current is then turned on and continueduntil the voltmeter and ampere-meter show that the current is no longerfusing the carbon and calcium to produce calcium carbid. This becomesevident when the voltage gets too low or the resistance too high. Duringthe operation the gases set free bythe decomposition of the lime andcoke seek the surface of the heap, where they burst into flame. Shouldthe flame at any time be too prominent, the workman should shovel alittle more of the mound onto the flame, as this undue prominence showsthe presence of a too ready escape for the gases. When the operation iscomplete, there is a white-hot nugget of calcium carbid surrounding ortaking the place of the core. preferably been destroyed and if made ofcarbonor coke forms an integral part of the calcium-carbid nugget. Thenugget is now lifted out of the mound and transported to a convenientplace where it is allowed to cool. A new core is substituted for the oldone, the mound of lime and coke heaped up around it, electricalconnection again made, and a new nugget formed.

We have found that in spite of the intense heat necessary for theformation of calcium carbid, namely, about 5,000 Fahrenheit, which hasto be maintained in the vicinity of the core, the surface of the mound,except where the gases are burning, is suiii'ciently The core has coolvto be handled readily. It does not heat the shovels of the workmen anddoes not even feel uncomfortably warm to the hand.

It is obvious that our improved process is of extreme simplicity, doingaway with all elaborate and expensive apparatus, and con sists virtuallyin the heating of the vertical center of a mound composed of pulverizedcoke and ground lime to a White heat by the passage through saidvertical center of an electric current along the conducting-core, whichpreferably becomes destroyed during the process.

We have found that simple pulverized lime and coke mixed in about equalproportions may be effectively employed in our improved process withoutprevious treatment.

This process, though particularly intended for the formation of calciumcarbid, may be employed with advantage in the formation of the carbidsof the other alkali metals and alkaline-earth metals by substitutingtheir oxids or compounds for the lime.

Simple mechanism for carrying our improved process into practicaloperation is shown in the accompanying drawing, in which A is a mound ofmixed coke and lime restin g upon the ground or floor B. At about thevertical center of this mound we set the lower electrode 0, which isconnected to a dynamomachine by the wire a.

D is the core, which is preferably of carbon, of smaller diameter thanthe electrode, and which rests upon the lower electrode in asubstantially vertical position through the vertical center of themound.

E is the upper electrode, in substantially vertical line with the lowerelectrode, and when in operation is supported only by the core D and thesurrounding mass of material. As these latter fuse and thereby shrink,the upper electrode is allowed to descend freely by reason of itsweight.

F is a simple form of supporting-frame for the electrode when not inuse. The electrode is mounted upon the slide-rods Z7 b, of goodconducting material, which pass through the insulating-sleeves c 0,attached to the frame F, and at their upper ends are connected to thewire d, which leads to the dynamo-machine. The electrode is lifted' awayfrom the mound, when not in use, by the chain G, passing over the pulleyf and secured to the roller g, which is free to revolve in onedirection, but is turned in the other direction by the crank h and heldin place by the pawland-ratchet device usual in such cases. This frame Fis a swinging frame, for obvious reasons.

H is a simple swinging frame carrying the lifting-ton gs I and adaptedto bring said tongs over the vertical center of the mound, into whichthey are adapted to descend and grasp the nugget, while still hot, andraise it out of the mound. The frame is then swung out of the way andthe nugget is deposited on any suitable transporting device. (Notshown.)

l/Ve claim 1. The above-described substantially-continuous process offorming calcium carbid which consists in forming a mound of coke andlime mixed in proper proportions around a core of conducting materialsupported in vertical position between two superposed electrodes,heating the vertical center of said mound to incandescence by passing anelectric current through said electrodes and core and maintaining saidcurrent until a nugget of calcium carbid is formed in said mound,permitting the upper electrode to descend freely as the supportingmixture beneath it is gradually reduced and fused, removing said nuggetwhile hot, inserting a new core, covering it with the material of saidmound and repeating the specified steps.

2. The above-described process of forming calcium carbid which consistsin forming a mound of coke and lime mixed in proper proportions around acore of conducting material supported in vertical position between twosuperposed electrodes, heating the vertical center of said mound toincandescence by passing an electric current through said electrodes andcore and maintaining said current until a nugget of calcium carbid isformed in said mound, permitting the upper electrode to descend freelyas the supporting mixture beneath it is gradually reduced and fused,removing said nugget, inserting a new core, covering it with thematerial of said mound and repeating the specified steps.

WILLIAM R. KING. FRANCIS WYATT. Witnesses:

J. KENNEDY, W. P. PREBLE, Jr.

